Hamamelis L., the witch hazel genus, is disjunctly distributed in eastern Asia mainly China and Japan and eastern North America. Compared to other Hamamelis species, only few studies have been done with H. japonica Sieb. et Zucc. In the present investigation, the chemical constituent study of the twig of H. japonica has performed for the first time. Three new monoterpenoid glycosides (1–3) together with 15 known compounds were isolated from the twig of H. japonica. The structures of compounds were determined based on extensive spectroscopic methods including 1D and 2D NMR and CD spectra data. Planar structure of aglycone of compounds 1 and 2 were p-menthane-1,2,8-triol, while compound 3 was a camphene. The remaining known compounds identified as three flavanoids (4–6), seven phenolics (7-13), one glycoside (14) and four stilbenes (15-17) by comparing with reported data.
Acknowledgements: This research was supported by Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Education, Science and Technology (NRF-2016R1A2B4006742 and NRF-2017R1A6A3A11029000) and by BrainKorea21PLUS program funded by National Research Foundation of Korea.